Push button control unit



Dec. 28, 1965 w. A. REIMER PUSH BUTTON CONTROL UNIT Filed OOt- 2, 1965 INVENTOR. William A. Reimer United States Patent spasms PUSH BUTTON CONTROL UNIT William A. Reimer, Villa Park, 11]., assignor to Automatic Electric Laboratories, Inc, Northlake, lil., a corporation of Delaware Filed Oct. 2, 1963, Ser. No. 313,214 3 Claims. (Cl. 2(ltl5) This invention relates in general to signal control apparatus. More particularly, the invention relates to an improved construction for a signal control unit having push buttons or keys for actuating relatively moveable contact springs associated with corresponding electrical circuits. The above type control unit can, for example, be used in a telephone subset as an alternative to the more conventional dial type signaling control unit. Each button or key could for instance represent a signal of a distinct frequency from which a particular partys telephone line is seized. The particular control unit can also be used in computers and other industrial applications.

In order for a control unit to be practical for use in the above applications it is necessary that it be reliable, economical, compact in size, and virtually noise free in operation. Accordingly, it is necessary that its construction be simple; that numerous assembly operations and close tolerance considerations be avoided.

in the prior art, push button-type control units were constructed in such a manner that the contact springs and wires thereto were all placed below the finger button. This required an overall increase in the depth of the package and in some instances, special shaped contact springs. Furthermore, a characteristic of the prior art construction was that they involved numerous parts and required many assembly operations.

Therefore, the principal object of the invention is to provide an improved construction for a push button signaling control unit.

Another object of the invention is to provide a push button control unit which is compact and substantially simplified over designs of the prior art.

Another object of the invention is to provide a push button control unit for a signaling system whereby conductors and contact springs thereof are operated by the side surfaces of the finger button rather than the bottom thereof.

Still another object of the invention is to provide a push button signaling control unit wherein critical tolerances and final adjustments are virtually eliminated.

In accordance with these objectives a feature of the invention is a frame structure that includes slats which are interlocked int-o rows and columns to form a cross-grid pattern and a plurality of. rectangular shaped cubicals or cells. The interlocking of the slats takes place by means of slots which extend from the edges of the slats and complement each other such that one slot fits into the other. The size of these slots are such that after the slats are assembled together no further securement means is needed to keep the slats interlocked together.

Another feature is that the slats carry conductors that are disposed on the surfaces thereof by printed circuit techniques and that form circuitry necessary to the control unit. Also, carried by the slats are contacts which are connected -or formed as a part of the printed conductors. Still another feature is the contact springs which are of a particular form and are fixed in grooves along the top and bottom edges of the slats. By varying the depths of the grooves a time sequence in the operation of the contact springs can be provided. In addition, both normally closed and normally open contact springs are disclosed in the invention. Still another feature of the construction is that each of the push button assemblies are placed in an individual cell of the frame structure to provide a stabilizing effect on them. Also, the sides of the individual push buttons are the means whereby the contact springs are either opened or closed. The contact springs on one side of a cell can be made to operate before a similar contact spring on an adjacent side of the cell by making the groove in which the first contact spring is in more shallow than the groove which receives the second contact spring. In this way the aforementioned time sequence in the operation of the various contact springs is established.

These and other objects and features of the invention will become apparent after a perusal is made of the following detailed description which makes reference to the accompanying drawings of which:

FiG. 1 shows a top view of an arrangement of a number of push button assemblies placed within a frame structure according to the invention.

FIG. 2 shows an enlarged perspective view of the construction details of the frame structure, and shows a single push button assembly located therein.

FIG. 3 is an exploded perspective view showing how the slats used in the frame structure are interlocked and also the details of the printed conductors, contacts, and the contact springs used in association with the slats.

FiG. 4 is an exploded perspective view of a push button assembly used with the frame structure.

FIG. 5 is a perspective view of a normally open contact spring used in connection with the control unit.

FIG. 6 is a perspective view of a normally closed contact spring used in connection with the control unit.

FIG. 7 is a cross-section view of a control unit according to the invention where the push button assembly thereof is in a restored state.

FIG. 8 is a cross-section view as shown in FIG. 7 where the push button assembly is in a depressed or operated state.

Referring now to the drawings, FIG. 1 shows an arrangement of ten push button assemblies 20 positioned in cells of frame structure 10. The frame structure here shown consists of a number of cross pieces or slats 13 and 14- which are arranged in rows and columns respectively. Although twelve cells are shown in the embodiment it is to be observed that the invention is not so limited. Any number of cells can be formed using the basic construct-ion disclosed by the invention which therefore depends on its application of the control unit.

FIG. 2 shows the contruction of frame structure 10 in more detail. There shown are slats 13 and 14, top plate 16, and bottom plate 15, in combination with push button assembly 20. The frame structure is made of a lightweight yet strong and durable material and forms a selfsupporting unit which could be considered a subassembly to a large control panel for example. Top plate 16 is secured to top edges 18 of slats 13 and 14, and bottom plate 15 is secured to the bottom edges 17 of the slats. The means for securement can be an adhesive medium, for example, or by some other means such as the combination of embossed portions and corresponding depressions which receive them. The latter scheme would enable the component parts to be quickly and easily clipped or snapped in place.

FIG. 3 illustrates the manner in which slats 13 and 14 are assembled and more specifically interlocked. The interlocking feature is afforded by means of slots 15 and slots 16 formed in slats 13 and 14 respectively. The slots extend from edges 17 and 18 of the slats to approximately their center. They are approximately the same length and the same width in order for them to be complementary with one another. Therefore, slot 15 is made to fit into slot 16 so as to run perpendicular to each other and so that the edges of the respective slots are flush with one another. According to the figure, only one slot is shown in each slat, however it is to be understood that at each intersection or crossing of slats 13 and slats 14 there is a pair of the aforedescribed complementary interlocking slots.

Carried by slats 13 and 14 are printed conductors 19, contacts 21 and 22, and contact springs 24 and 25. The conductors are of the printed type and disposed on the slats by any of the well known techniques used in the art of printed circuitry. The conductors are on one or both sides of the slats depending upon the particular use of the control unit and the capacity desired from it. The particular pattern which the conductors follow is by and large arbitrary. Adjacent to conductors 1a are contacts 21 and 22. These are pads of contact material positioned adjacent the conductors which cooperate with contact springs 24 and 25. The contacts 21 and 22 are shown in pairs in order to be complementary to the contact springs.

Along the edges of slats 13 and 14 are grooves 23 and 26. These are located approximately adjacent to the locations of contacts 21 and 22. The grooves serve as the means for locating contact springs 24 and 25 and further fix them after top plate 16 and bottom plate are added to the frame structure. Therefore no additional fastening means is required to secure the contact springs to the frame structure. Moreover, the assembly of the contact springs can be done manually and without complication. Further, no critical adjustments have to be performed on the contact springs because they are not of the critical type. In this respect the invention provides an improved construction; one that is substantially simplified over the constructions shown heretofore.

FIG. 5 shows the details of the aforementioned contact spring 24. This is a normally open contact spring made of a flat resilient material and preformed in such a way to consist of three portions: an end portion 42, center portion 45 and a contact portion 44. The end portion 42 is formed as a square hook in order for it to fit and be properly received by groove 23. Center portion 45 is curved away from the slat to form a crest upon and against which the finger button, described subsequently, rides. The curved form is necessary for the contact spring to close as the side surface of the push button assembly comes down and for contact portion 44 to engage contacts 21, see FIGURES 7 and 8.

FIG. 6 shows contact spring 25 which is the normally closed type. It also is preformed and consists of three portions: an end portion 43, a contact portion 47, and a free end portion 46. End portion 43 is in the form of a square hook and is received by groove 26 shown in FIG. 3. The contact portion 47 is made complementary to contacts 22.and consists of a shoulder portion or bulged out projection. End portion 46 is made so that it engages with a side surface of the push button assembly as it is depressed and is flared out to facilitate this end. Thusly, is the contact spring opened.

Conductors 19 disposed on slats 13 and 14 are terminated, for example, in some termination means (not shown) which may be afiixed to the slats. The particular means can for example be a certain type of terminal block, or in the alternative eyelets. Either of these would be connectable to the electrical system. The control unit here disclosed therefore is constructed in a manner that with proper termination means it could be plugged in a circuit board.

FIG. 4 is an exploded view of the aforementioned push button assembly 20. As stated and shown in the drawings the assembly is designed for use in a cell of the control unit. Further, it consists of few parts which are easily assembled. Each are of simple design and except for the restoring means and stop means are preferably molded. Close tolerances are avoided without sacrificing ease and quietness of operation.

Included in the assembly is finger button 28, wear resistant insulator 29, a shank portion 31, a restoring spring 34 and a stop spring 35. Finger button 28, insulator 29, and shank portion 31 are all preferably molded and made of a tough, durable, and wear resistant material, such as a Mylar plastic. More specifically finger button 23 is shaped as a pyramid having a square base, for example, The square base corresponds to the configuration of the individual cell in order to serve to stabilize the up and down movement of assembly 20. Secured to the bottom surface of button 28 is wear resistance insulator 29 which is approximately the same size in cross-section as the base portion of the finger button. In the alternative, finger button 28 and insulator 29 can be made as one integral piece. As shown, however, insulator 29 serves as the means whereby excessive transverse or lateral movement in the assembly is avoided. Thusly is the push button assembly stabilized. It should be noted that the finger button can also be round shaped.

Located in the approximate center of insulator 29 is a rectangular aperture 30 which receives a similarly shaped end portion 32 of shank 31. The end portion 32 projects through aperture 39 to where shoulder 36 rests against the bottom surface of insulator 29. In the case where finger button 28 and insulator 29 are made as one piece then the end portion 32 would secure the integral part.

The opposite end of shank 31 includes end portion 33 which has a reduced cross-sectional area from that of the center portion in order to accomplish the formation of shoulders 37. The shoulders serve as a stop to the downward movement of the assembly. Positioned intermediate insulator 29 and bottom plate 15 is coil spring 34 which is made of a resilient material such as spring steel for instance. The spring is the means for maintaining the push button assembly in a restored position.

Near the end of end portion 33 is groove 38, which receives stop ring 35. The stop ring 35 is the means used to retain assembly 20 within a particular cell. The movement of assembly 20 is thus limited by a stop ring 35 at the one end, and shoulder 37 at the opposite end.

In conclusion, it should now then be apparent that the improved construction for a control unit of this type is hereby substantially simplified over those of the prior art. Specifically, it should be clear that the control unit package is made more compact by virtue of the contact springs being located as well as operated by the sides of the button. Also, it should be realized that the number of parts used in the construction have been reduced from the number commonly employed heretofore. Close tolerances and final adjustments that heretofore plagued the constructions of the above type control units have been virtually eliminated. The majority of parts to the unit are assembled merely by fitting them together. Use of screws and other fastening means have been minimized. All these characteristics and features advance the state of the art of control units using push buttons making it more feasible and desirable to employ them in greater numbers and applications.

The invention has been described in detail in connection with a preferred embodiment, however, it is to be understood that this was done merely by Way of example and not intended as a limitation to the spirit and scope of the invention as only defined by the following claims.

What is claimed is:

1. Apparatus for controlling signals to an electrical system comprising: a frame structure having a plurality of slats of insulating material having complementary slots therein which interlock at points of cross section to form the walls of rectangular shaped cells; a push button assembly received in each of said cells for longitudinal sliding movement and including a shank; means cooperating with one end of each said shank for containing the r corresponding assembly within the respective cell; a restoring spring surrounding the shank at said end; finger button means at the other end of each said assembly, said finger button means including an insulator piece having lateral guide surfaces slidably movable along said cell Walls; relatively movablecontact springs carried by said slats and located within each said cell and actuated in response to the movement of the corresponding assembly; termination means; and circuit conductors printed in a predetermined pattern on said slats and extending from said contact springs to said termination means.

2. Apparatus for controlling signals to an electrical system as claimed in claim 1, wherein said circuit conductors are printed on said slats so as to skirt the slots at points of cross-section.

3. Apparatus for controlling signals to an electrical system as claimed in claim 1, wherein said movable contact springs are positioned in grooves formed in the slats, certain ones of said grooves being more shallow than cer tain other ones of said grooves.

References Cited by the Examiner UNITED STATES PATENTS 2,841,044 7/1958 Beach et al. 2005 X 2,939,100 5/1960 Watts 33918 2,964,986 12/ 1960 Johnson 200-5 X FOREIGN PATENTS 750,244 6/ 1956 Great Britain.

- KATHLEEN H. CLAFFY, Primary Examiner.

MORRIS GINSBURG, Assistant Examiner. 

1. APPARATUS FOR CONTROLLING SIGNALS TO AN ELECTRICAL SYSTEM COMPRISING: A FRAME STRUCTURE HAVING A PLURALITY OF SLATS OF INSULATING MATERIAL HAVING COMPLEMENTARY SLOTS THEREIN WHICH INTERLOCK AT POINTS OF CROSS SECTION TO FORM THE WALLS OF RECTANGULAR SHAPED CELLS; A PUSH BUTTON ASSEMBLY RECEIVED IN EACH OF SAID CELLS FOR LONGITUDINAL SLIDING MOVEMENT AND INCLUDING A SHANK; MEANS COOPERATING WITH ONE OF EACH SAID SHANK FOR CONTAINING THE CORRESPONDING ASSEMBLY WITHIN THE REPECTIVE CELL; A RESTORING SPRING SURROUNDING THE SHANK AT SAID END; FINGER BUTTON MEANS AT THE OTHER END OF EACH OF SAID ASSEMBLY, SAID FINGER BUTTON MEANS INCLUDING AN INSULATOR PIECE HAVING LATERAL GUIDE SURFACES SLIDABLY MOVABLE ALONG SAID CELL WALLS; RELATIVELY MOVABLE CONTACT SPRINGS CARRIED BY SAD SLATS AND LOCATED WITHIN EACH SAID CELL AND ACTUATED IN RESPONSE TO THE MOVEMENT OF THE CORRESPONDING ASSEMBLY; TERMINATION MEANS; AND CIRCUIT CONDUCTORS PRINTED IN A PREDETERMINED PATTERN ON SAID SLOTS AND EXTENDING FROM SAID CONTACT SPRINGS TO SAID TERMIANTION MEANS. 